Taper attachment construction



Feb. 16, 1943.

C. A. BICKEL T AFER ATTACHMENT CONSTRUCTION Filed June 10, 1940 4 Sheets-Sheet 1 A TTOAWE Y3 Feb. 16, 1943. c. A. BICKELY 1 3 TAPER ATTACHMENT doNsTRucTIoN Filed June 10,. 1940 4 S heetS-Sheet. 2

WMM \\\\\\\\\\\m Y ATM/M'EYS C. A. BICKEL TAPER ATTACHMENT CONSTRUCTION 4 Sheets-Sheet 3 Filed June 10, 1940 Z/ZZ Arm/mm Feb. 16, 1943. c,=A. BICKEL TAPER ATTACHMENT CONSTRUCTION 4 Sheets-Sheet 4 Filed June 10, 'l940 A TTOIF/VEYS Patented Feb. 16, 1943 UNITED' STATES TENT OFFICE TAPER ATTACHMENT CONSTRUCTION Clifford A. Bickel, Sidney, Ohio, assignor to The Monarch Machine Tool 00., Sidney, Ohio, a

corporation of Ohio 2 Claims.

This invention relates to taper cutting devices which are to be positioned on a lathe or other turning machines.

An object of the invention is to provide a taper cutting apparatus wherein the friction of the thrust transmitted through the device is reduced to a minimum to permit accurate cutting of tapers on a workpiece.

Another object of the invention is to provide a plurality of anti-friction devices positioned between adjacent cooperating surfaces each of which consists of a plurality of rotary bearing elements and which are so positioned to prevent or reduce friction to a minimum between th cooperating sliding surfaces which guide the movement of the movable members of the taper cutting device.

Another object of the invention is to provide a plurality of anti-friction bearing devices having angularly positioned bearing faces which cooperate with guide members to position a movable slide member upon a stationary carriage bracket both vertically and laterally.

A still further object of the invention is to provide an arrangement of anti-friction bearing elements between a sliding member and a stationary member whereby the bearing elements will position the sliding member upon the stationary member and will assume any thrust caused upon the sliding member.

A still further object of the invention is to position a plurality of anti-friction devices, comprising a plurality of rotary bearing elements, between a movable member and a stationary carriage in such a manner that the anti-friction dea vices are adjustable to alter a horizontal plane of the sliding member upon the stationary member and to position this plane vertically and laterally with respect to the stationary member.

Another object of the invention is to provide a plurality of anti-friction bearing devices between adjacent parallel sliding surfaces which devices consist of a race filled with a plurality of needle bearings.

Further objects and advantages will be apparent from the description and the drawings which follow.

In the drawings:

Figure 1 is a top elevational plan view of a turning machine to which the taper cutting device of this invention has been attached.

Figure 2 is a transverse cross-sectional view taken along line 22of Figure 1.

Figure 3 is a horizontal cross-sectional view taken along line 3-3 of Figure 2.

Figure 4 is a horizontal cross-sectional view taken along line 4'4 of Figure 2 and shows a por tion of the carriage bracket in which an adjusting screw is positioned. I

Figure 1 is a cross-sectional view similar to that of Figure 2 showing a modified arrangement of the anti-friction bearing devices. a

Figure 5 is a cross-sectional view similar to that that of Figure 2 showing a still further modified form of the anti-friction bearing devices.

Figure 7 is a partial cross-sectional view of the slide and carriage bracket showing an inversion of the bearing arrangement disclosed in Figure 2.

Figure 8 is a partial cross-sectional view of the slide and carriage bracket showing an inversion of the bearing arrangement disclosed in Figure 6.

Figure 9 is a partial cross-sectional View of the slide and carriage bracket showing an inversion of the bearing arrangement disclosed in Figure 5.

Figure 10 is a partial transverse cross-sectional view of the slide and carriage bracket showing another form of an anti-friction bearing which can be positioned between the slide and carriage bracket.

Figure 11 is a partial horizontal cross-sectional view taken along line H II of Figure 10.

In general, the device of this invention is a device for cutting tapers longitudinally upon a workpiece positioned within a lathe or other turning machine. The device is attached to the carriage of the lathe in such a manner that one portion, or carriage bracket of the device, moves longitudinally along the lathe bed with movement of the lathe carriage. Another portion, or the slide of the device, is adapted to be retained in a stationary position through means of an anchor bracket which is secured to the bed of the lathe. A swivel member is pivotally mounted upon the slide and is arranged so that it can be positioned at an angle with regard to the longitudinal movement of the carriage of the lathe. A shoe or follower engages the angularly positioned swivel-and is caused to follow the angular path formed by the guideways of the swivel since the shoe or follower is interconnected with the carriage bracket which is secured to the lathe carriage. Since the 'carriage bracket and'follower' move relative to the swivel and slide it is seenthat the shoe is capable of transmitting an angular movement simultaneously with the longitudinal movement thereof.

The shoe or follower is connected to the cross slide positioned upon the carriage of the lathe. in such a manner that the transverse movementcaused by movement of the shoe will be transmitted to the cross slide of the lathe and thus to the cutting tools positioned thereon.

When performing a taper cutting operation upon a workpiece positioned within the lathe considerable transverse thrust is transmitted through the shoe and swivel to the slide, thereby making it diihcult for the slide and shoe to move relative to the carriage bracket and swivel. The anti-friction bearing elements positioned between the slide and the carriage bracket and between the swivel and shoe of this invention assume the friction caused by this transverse thrust, thereby providing means to permit free movement between the slide and the carriage bracket.

In this invention a lathe or turning machine H] is provided with a bed |2 upon which ways I3 are positioned longitudinally upon the bed |2. A head stock [4 is located at one end of the bed 2 and is provided with conventional mechanism within the head stock to drive a-live spindle l5. At the opposite end of the lathe l there is a tail stock I6 to be moved to and fro along the ways l3 to adjust the position thereof with respect to a workpiece to be positioned between the live center I5 and the dead center |'I positioned within the head stock It. A clamping lever (not shown) is mounted upon the tail stock l6 and is adapted to clamp the tail stock l6 in position upon the ways l3, lever I8 is provided to lock the spindle and dead center within the tail stock IS. The mechanism operated by the lever I8 is of any conventional type and is well known in the art.

A carriage 22 is mounted upon the ways |3a also positioned upon the upper surface of the bed |2 of the lathe Ill. The carriage 20 is arranged so that it can be driven toand fro along the ways |3a by means of the usual feed rod (not shown) mounted adjacent the forward wall of the lathe I0 and connected with the driving mechanism of the lathe in conventional manner. An apron 2| depends from the forward edge of the carriage 20 and is adapted to support various controls for operation of the lathe mechanism, and particularly the controls for controlling movement of the carriage 2!! and a cross slide 22. The .cross slide 22 is positioned transversely upon the carriage 20 and'is guided in its transverse movement by' the ways 23 which provide a dovetail type sliding joint between the ways 23 and the cross slide 22. A cross feed screw 24 is positioned transversely of the carriage 20 and engaes a cross feed nut (not shown) upon the cross slide 22. The cross feed screw 24 is connected to the driving mechanism of the lathe in a conventional manner for driving the cross slide 22 transversely of the carriage 20.

A compound tool rest 25 is mounted upon the cross slide 22 and is provided with the usual swivel plate 25 for permitting angular positioning of the compound tool rest 25 with respect to the cross slide 22. A tool post 21 is mounted upon the tool rest 25 and is adapted to carry a clamping means 28 which is provided for securing the tool post 21, and a tool positioned therein, upon the tool rest 25.

As heretofore mentioned suitable controls are provided upon the apron 2| depending from the carriage 2B for controlling the operations of the carriage 29 and for controlling the transverse movement of the cross slide 22. These controls may 'consistof a hand wheel 39 which engages the feed rack (not shown) of the lathe I0 for transporting the carriage 20 longitudinally along the ways l3a. A hand wheel 3| may be provided for manually advancing and retracting the cross slide 22 transversely upon the carriage 26. A micrometer indicating wheel 32 may be positioned in operative association with the hand wheel 3| to indicate the travel of the cross slide 22. A suitable hand wheel 33 and a micrometer indicating head 34 are provided upon the compound tool rest 25 for controlling the movement of the tool upon the rest and indicating said movement.

The cross feed screw 24 is interconnected with a taper cutting attachment 40 secured to the carriage 20 in. such a manner that when the taper cutting attachment 4!] is arranged to transmit an angular motion simultaneously with longitudinal movement of the carriage 23, interconnecting driving means between the taper cutting attachment 4!] and the cross feed screw 24 will cause the cross feed screw to be urged transversely of the carriage 20, without causing the same to revolve. The cross feed screw 24 will thus carry the cross slide 22 transversely upon the carriage 20 simultaneously with longitudinal movement of the carriage 20.

This function of the cross feed screw in transmitting an angular motion upon the cross slide 22 with simultaneous longitudinal movement of the carriage 20, without rotation of the cross feed screw 24, requires that a telescopic driving arrangement be provided between the cross feed screw 24 and the driving mechanism for the lathe Hi. This telescopic arrangement (not shown) is such that the feed rod of the lathe may drivingly engage the cross feed screw 24 to permit rotation thereof to cause transverse movement of the cross slide 22 upon the carriage 2D, or when the cross feed screw 24 is disconnected from the feed rod of the lathe a sliding engagement between the cross feed screw 24 and the feed rod of the lathe is brought into actionto premit the cross feed screw 24 to be moved transversely of the carriage 2|) through a manually controlled push or pull upon the cross feed screw 24. These telescopic driving connections between a cross feed screw and the feed rod of the lathe, are well known in the art and further description thereof is not deemed necessary.

The taper cutting attachment 40 consists of a carriage bracket 4| which is secured to the carriage 20 by means'of the bolts 42 whereby the carriage bracket 4| will be caused to move longitudinally upon the ways |3a of the lathe l0 when the carriage 20 is moved to and fro upon said lathe. A slide member 43 i positioned in sliding engagement with the carriage bracket 4| through suitable anti-friction bearing elements which will hereinafter be more fully described. The slide 43 is retained in a stationary position with respect to the bed |2 of the lathe II! by means of an anchor bracket 44 and an anchor rod 45. The anchor rod 45 is attached to the slide 43 as at 46. The opposite end of the anchor rod 45 extends through the anchor bracket 44 and is secured thereto by means of the retaining nuts 41 which are in threaded engagement with the anchor rod 45 to permit adjustment of the rod with respect to the anchor bracket 44. The anchor bracket 44 is provided with suitable clamping means for securing the bracket to the way |3a upon the bed |2 of the lathe Ill and may consist of a binding bolt 48 which may extend through the anchor bracket 44 and engage the underside of the way |3a and bind the bracket 44 thereupon.

A swivel v|! is pivotally mountedupon the slide 43'bymeans of a ivotpostvl' (see: Figure 2), to permit the swivel 50' to. be arranged ang-ularly with respect to the axis of rotation of a workpiece positioned between thelive center I5 and the dead. center ll of the lathe IG'. At one end of the swivel 59 there is provided a micrometer adjusting attachment 52'which isada pted'to engage a gear segment 53 positioned upon? the end of the: swivel 53. This micrometer adjusting device is provided for accurately controlling the angular position of the swivel 53 upon the slide- 43'. Binder screws 54 are provided at either end of the swivel 50 and are adapted to extend through the swivel intoengagement with the slots 55 positioned in the slide 43, and are provided for retaining th swivel 50 in position after having been set by means of the micrometer adjusting device 52.

A shoe orfollower 60 engages the swivel 53' and is guided thereupon in such a manner that the path'of movement of the shoe 6|lfwill be coincident with the angularity of the swivel 5'3: The shoe '60 is secured to a draw-bar 6| by means of a stud 62' which extends through a bushing 63 which passes through the draw-bar 6 I. A washer 65 is placed upon the stud 62 above the bushing 63 and the draw-bar 5|. A nut 64 is in threaded engagement with the end of the stud 62. The shoe or follower 63 is thus pivotally positioned upon the draw-bar '6 I, and after the angularity of.

the swivel 50 has been set, the shoe 50 will cause a transverse movement to' be transmitted. through the draw-bar 6| when the shoe is moved longitudinally with respect to the swivel 50.

To provide lateral movement of the shoe 53 with respect to the swivel 5|!- the draw-bar 6|, upon which the shoe 60 is mounted, is retained in a guided relationship upon the carriag bracket 4"! Guide brackets 55 and 65 are positioned upon opposite sides of the carriage bracket 4| andare provided with guideways 61 and iifirespectively within which the draw bar 6| is in sliding and guided engagement. A cover plate 59 is positioned adjacent the top surfaces of the brackets 65 and 66 and is retained upon the brackets by means of the bolts 10. This cover plate, inccoperation with the guidew'ays '51 and 68 in the brackets 65 and 66 respectively, provides means for retaining the draw-bar 6| within-the guideways 61 and 68.

The draw-bar 6| is connected in operative asso' ciation with the cross feed screw 24 many suitable manner whereby the cross feed screw 'Z can be mounted rotatively upon the draw-bar 6!, while at the same time longitudinalmovement of the cross feed rod 24 with respect to the' drawbar -51 will be prevented. Many specific methods of so mounting the cross feed rod tothe draw bar could be provided and it is not believed an exact disclosure or further description of such a method is required.

In this invention the slide 43 is mounted upon the carriage bracket 4| through a plurality of anti-friction bearing devices.- These devices comprise a pair of anti-friction bearing devices '15 and each of which consists of a multiplicity of rotary bearing elements or ball bearings. The ball bearing anti-friction bearing device i5 is mounted upon a pin 1? and the ball bearing anti-- friction bearing device 75 is mounted upon a pin- 18. These pins 1'! and 18 are disposed angularly with respect to each other and are mounted upon an insert or gib 19 which: is positioned within a recess 8!). The recess 80 extend longitudinally within a vertically extending wall 8| of the carriage bracket 4|. The gib'l9'is retained within the recess by suitable fastening means.

Since the ball bearing members 75 and T5 are positioned upon their rotational axes upon the pins 17 and 78 which are disposed angularly with respect to each other, it can be seen that the bearing faces of the ball bearing members 15 and 16 will be disposed angularly with respect to each other, whereby a substantially wedge shaped or V-shaped bearing surface is provided for engagement with a guide member 82 positioned upon the slide 43. The guide member 82 is secured to the slide 43 by use of suitable bolts 83. The forward faces of the guide member 32, which are adapted'to engage the bearing faces of the ball bearing members 15 and 16, are arranged at the same angle of inclination as the cooperating faces of the ball bearing members 15 and 16 whereby bearing surfaces 84 and 85 are provided between the bearing members 15 and 15 respectively and their cooperating faces upon the guideway 82.

A plurality of these anti-friction bearing de- :vices, each comprising a pair of ball bearing anti-friction devices, may be positioned longitudinally along the vertically extending wall 8| of the carriage bracket 4| and engage the guide- Way 82 of the slide 43, which guideway is also positioned longitudinally upon the slide 43 for engagement with the anti-friction bearing devices mounted upon the adjacent cooperating wall 8| of the carriage bracket 4|.

A similar arrangement is provided along the opposite parallel wall of the slide 43 and the cooperating vertically extending wall 90 of the carriage bracket 4|. The arrangement adjacent thewall 90 of the carriage bracket 4| consists of the ball bearing anti-friction devices 92 and 93 mounted upon angularly disposed bearing pins 94' and 95. These bearing pins 94 and 95 are positioned within an insert or gib 36 positioned within a recess 8'! provided longitudinally within the wall 9!) of the carriage bracket 4|. This gib 96 may be retained in the recess 9'! by any suitable fastening means. A guideway 98 secured to the slide 43 by suitable bolts is provided with angularly disposed bearing faces 99 and I00 which cooperate with the angularly disposed bearing faces of the ball bearing anti-friction devices 92 and 93. It is thus seen that the positioning of the angular positioning of the ball bearing anti-friction devices 92 and 93 provide ing and. guideway surfaces provided. between the ball bearing members 15 and 16 and the cooperatingguideway 82 and the ball bearing members 92 and 93 and-the cooperating guideway member '98 it is seen that there isv provided an arrangement whereby the slide 43 is retained in a horizontal position and directly supported by the respective ball bearing, and guideway surfaces.

When operating the taper cuttingv attachment so as to cause movement of the shoe along the swivel-5d considerable transverse thrust is transmitted from the draw-bar 5| to the slide 43 which must lee-assumed by the anti-friction bearing-elements positionedbetween the slide 43 and the vertically extending walls BI and of the carriage bracket 4|. It is thus seen that the construction of the device, as heretofore dis,

closed, performs two functions in that the antifriction bearing devices support the slide 43 upon an anti-friction bearing surface and also assume any transverse thrust transmitted to the slide 43 by the draw-bar 6| and divide this thrust between a plurality of anti-friction bearing devices to obtain a more freely operating slide member.

To reduce the friction caused between the shoe 69 and the swivel 59 caused by the transverse thrust of the draw-bar 6|, anti-friction bearing devices I62 and I93 are provided between adjacent cooperating walls of the shoe 60 and the swivel 59. These anti-friction bearing devices I92 and I33 engage upwardly extending parallel walls I04 and I95 respectively.

To adjust the work clearance between the ball bearing anti-friction devices 15, 16, and 92, 93, and their cooperating guideways 32 and 93, the insert or gib 19 is provided with a tapered wall which cooperates with a similarly tapered wall of the recess 8|, as indicated at I06. A retaining screw I91 is positioned at either end of the gib 19 and is in threaded engagement with a threaded hole I98 placed in the wall 8| and adjacent the tapered wall I96. This screw I91 has an enlarged head I99 which engages the gib 19. Adjustment of the screw I61 will cause transverse movement of the gib 19 thereby moving the anti-friction bearing devices 15 and 16 transversely against the guideway 82, thus forcing the opposite guideway 98 into engagement with the anti-friction bearing devices 92 and 93.

In Figure there is shown a modified arrangement of the anti-friction bearing supports between the slide and carriage bracket of the taper turning device wherein single anti-friction bearing elements provide the means for vertically supporting the slide upon the carriage bracket and for assuming the transverse thrust of the slide. In this arrangement I provide a carriage bracket I25 which is secured to the carriage 20 of the lathe by means of suitable bolts I26. Antifriction bearing elements I21 and I28 are mounted upon their rotative axes by means of studs I29 and I33 respectively. These studs I29 and I39 are provided with reduced end portions I3! and I32 respectively which are threaded, and are in threaded engagement with tapped holes I33 and I34 respectively, positioned in the carriage bracket I25. Each of the anti-friction bearing elements I21 and I28 consists of a multiplicity of rotary bearing elements I35. The outer race I36 of the bearing element I21 and the outer race I31 of the bearing element I23 are provided with angularly disposed bearing faces which provide a substantially wedge shaped bearing surface thereupon. A slide I49 is provided with depending walls MI and I42 extending longitudinally of the slide I49 and in parallel relation with each other. A guideway or a gib I43 is positioned longitudinally within the wall MI and a guideway or a gib I44 is positioned longitudinally within the wall I42 of the slide I49. The guideway I43 is provided with a recess I45 and the guideway I44 is provided with a recess I46, said guideways being positioned in such a manner that said recesses engage the wedge shaped bearing faces of the races I36 and I31 of the antifriction bearing devices I21 and I23 respectively.

A plurality of the anti-friction bearing devices I21 and I28 may extend longitudinally of the carriage bracket I25 and adjacent the depending walls MI and I42 of the slide I49 whereby a plurality of bearing elements are provided to support the slide I49 in a vertical position with respect to the carriage bracket I25 and to assume any transverse thrust transmitted through the slide I49. The guideway or gib I43 is adjustable in the same manner as the gib 19, disclosed in Figure 2, by means of a screw I41.

A swivel I56 is pivotally mounted upon the slide I49 by means of a pin I5I and is provided with upwardly extending walls I52 and I53 which engage anti-friction bearing elements I54 and I55 respectively, suitably mounted upon a shoe or follower I69. The shoe or follower I60 is secured to the draw-bar 6| by means of a pin I62 extending through a bushing I63a upon which a washer I65 is mounted adjacent the slot I63 and is retained thereon by means of a nut I64 in threaded engagement with the end of the pin I62.

By the use of this arrangement a single antifriction bearing element, comprising a multiplicity of rotary bearing elements, can be used to vertically position a slide with respect to a carriage bracket and assume the transverse thrust of the carriage bracket.

In Figure 6, there is shown another modified arrangement of the positioning of anti-friction bearing devices, each comprising a multiplicity of rotary bearing elements, wherein the bearing devices can be adjusted to permit vertical adjustment of the horizontal plane of a slide with respect to a carriage bracket and wherein lateral adjustment may also be accomplished.

In this arrangement I provide a carriage bracket I15 which can be suitably mounted to the carriage 29 of the lathe I0. The carriage bracket I15 is provided with a recess I16 extending longitudinally within the same. An insert or gib I11 is positioned within a recess I18 provided in the bottom wall of the recess I16, and which extends longitudinally of the carriage bracket I15 and adjacent to and parallel with the Vertical wall of the recess I15. Anti-friction bearing devices I19 are mounted upon the gib I11 by means of bearing pins I39. A plurality of these devices may extend along the length of the gib I11. The bottom wall of the recess I18 is provided with a taper extending longitudinally of the recess and the bottom cooperating wall of the gib I11 is provided with a corresponding taper to cooperate with the bottom wall of the recess I18 in such a manner that the gib I11 may be raised or lowered within the recess I18 to adjust the vertical position of the bearing surfaces of the anti-friction bearing devices I19. This adjustment is of a construction like that disclosed in Figure 4.

A similar anti-friction bearing arrangement is provided along the opposite edge of the wall of the recess I16 and consists of an adjustable insert or gib I8I upon which an anti-friction bearing device I32 is mounted upon a bearing pin I83. This bearing device is also adjustable vertically to position the bearing face of the anti-friction bearing device I82.

A slide I99 is positioned within the recess I16 of the carriage bracket I15 and has the bottom face thereof supported upon the anti-friction bearing devices I19 and I62 respectively. These bearing devices are positioned adjacent the outer edges of the slide I99. Alteration of the vertical position of the bearing surfaces of the anti-friction bearing devices We and I32 will thus be caused to alter the horizontal plane of the top surface of the slide I96 whereby vertical adjustment of the slide I93 with respect to the carriage bracket I15 may be obtained.

Similarly constructed anti-friction bearing devices I84 and I85 are positioned between adjacent parallel vertical side walls of the recess in the carriage bracket I15 and the slide I90. Either or both of these anti-friction bearing devices can be made adjustable in the same manner as the anti-friction bearing devices I19 and I82, the adjustment however being in a lateral direction rather than a vertical direction, whereby the work clearance between the bearings and the side walls of the slide I90 can be adjusted, as well as providing means to laterally position the slide I90 upon the carriage bracket I15.

In Figure 7 I disclose a modified arrangement of the bearing support, as disclosed in Figure 2, wherein the anti-friction bearing devices 15a and 16a are mounted upon the slide 43a rather than on the carriage bracket as disclosed in Figure 2.

The guideway 820, used in this arrangement is positioned upon the carriage bracket 4Ia rather than upon the slide as disclosed in Figure 2. This arrangement is thus an inverted position of the bearing elements with respect to the slide and the carriage bracket. However, the functon of the anti-friction bearing device is the same as,

disclosed in Figure 2, the arrangement of this modification showing however, a manner whereby the transverse thrust of the slide 43a may be inwardly against the carriage bracket Ma rather than outwardly, as disclosed in Figure 2.

Figure 8 shows a modified arrangement of the bearing elements as disclosed in Figure 6 wherein the anti-friction bearing devices H911 and I84a are positioned upon the slide I90a rather than upon the carriage bracket IIa whereby the adjustable devices are positioned in the slide I900, rather than in the carriage bracket I'I5a, as disclosed in Figure 6.

Figure 9 is a modified arrangement of the bearing position disclosed in Figure 5 wherein the anti-friction bearing device IZ'Ia is mounted upon the slide I4lla and wherein the guideway M311 is mounted within the carriage bracket I25a. This arrangement shows an inversion of the bearing arrangement of Figure 5 wherein the bearing thrust is outward against the carriage bracket rather than inward against the bearings as disclosed in Figure 5.

In Figures 10 and 11 there is shown a modified form of an anti-friction bearing device wherein a multiplicity of needle-type bearings are used for the anti-friction bearing members. In this arrangement the carriage bracket 200 is provided with an elliptically shaped recess I having the axis of the ellipse positioned vertically. A similar elliptically shaped recess 202 is provided in the carriage bracket 200 and has the axis of the ellipse positioned horizontally. Elliptically shaped inserts 203 and 204 are positioned within the recess 20I and 202 respectively and are positioned with respect to the walls of the recesses to provide an elliptically shaped passageway, the outer face of which will provide :an outer race for a multiplicity of needle bearings while the inner face will provide the inner race for a multiplicity of needle bearings. A plurality of small diameter rods are positioned vertically or horizontally within the respective passageways and are closely adjacent each other whereby a continuous, or substantially continuous, bearing surface can be provided adjacent a face of the passageway against which a movable surface may be frictionlessly guided. Cover plates 205 and 206 enclos the needle bearings within the passageways formed by the recesses 20I and 202 respectively, the plates being secured to the carriage bracket 200 by means of bolts 201 and 208.

The construction of the frictionless bearing surface between the movable bearing surfaces of a slide and a carriage bracket provide means whereby the transverse operating thrust caused by operation of the device, and transmitted through the device to the bearing surfaces, can be assumed, and the slide member be caused to frictionlessly slide Within the carriage bracket when the taper cutting device is in operation upon a lathe or other turning machine. The degree of transverse thrust transmitted by the draw-bar 6| through the shoe 60 and swivel to the slide 43 increases tremendously as the angle of inclination of the swivel is increased with respect to the axis of rotation of the workpiece in order to cut steep tapers. Thus, the thrust can become so great as to bind the moving parts of the taper cutting device that it is, therefore, imperative that the friction between the moving parts be reduced to a minimum. By dividing the friction between vari ous bearing surfaces each bearing surface will be caused to assume less friction, thereby providing an arrangement which will slide more freely.

It will be understood that I desire to comprehend within my invention such modifications as come within the scope of the claims and the invention.

Having thus fully described my invention, what I claim as new and desired to secure by Letters Patent, is:

1. In a machine tool, a'carriage bracket, a slide adapted to be moved longitudinally with respect to said carriage bracket and slidably guided thereon, and anti-friction bearing devices interposed between adjacent parallel surfaces of said slide and said carriage bracket including an outer race formed by said slide and bracket, an inner race, and a multiplicity of needle bearings between said races said carriage bracket having an elliptical recess and an elliptically shaped insert inserted in said recess, the axes of said ellipses being in a vertical plane, said carriage further having a second elliptical recess and a second elliptical insert in said recess, said last named recess and insert being in a horizontal plane, the spaces formed between each recess and insert forming raceways for said bearing devices.

2. In a machine tool, a carriage bracket, a slide adapted to be moved longitudinally with respect to said carriage bracket and slidably guided thereon, and anti-friction bearing devices interposed between adjacent parallel surfaces of said slide and said carriage bracket including an outer race formed by said slide and bracket, an inner race, and a multiplicity of needle bearings between said races, said carriage bracket having an elliptical recess and an elliptically shaped insert inserted in said recess, the axes of said ellipses being in a vertical plane, said carriage further having a sec- 0nd elliptical recess and a second elliptical insert in said recess, said last named recess and insert being in a horizontal plane, the spaces formed between each recess and insert forming raceways for said bearing devices, and a cover for said first recess for enclosing said bearing devices, said cover having a flange forming a hold-down plate for said slide,

- CLIFFORD A. BICKEL. 

